In 111 BCE, the Han dynasty conquered Nanyue during its expansion southward and incorporated what is now northern Vietnam, together with much of modern Guangdong and Guangxi, into the expanding Han empire.^[38] During the next several hundred years of Chinese rule, sinicization of the newly conquered Nanyue was brought about by a combination of Han imperial military power, regular settlement and an influx of Han Chinese refugees, officers and garrisons, merchants, scholars, bureaucrats, fugitives, and prisoners of war.^[39] At the same time, Chinese officials were interested in exploiting the region's natural resources and trade potential. In addition, Han Chinese officials seized fertile land conquered from Vietnamese nobles for newly settled Han Chinese immigrants.^[40] Han rule and government administration brought new influences to the indigenous Vietnamese and Vietnam as a Chinese province operated as a frontier outpost of the Han Empire.^[41] The Han dynasty was desperate to extend their control over the fertile Red River Delta, in part as the geographical terrain served as a convenient supply point and trading post for Han ships engaged in the growing maritime trade with various South and Southeast Asian Kingdoms and the Roman Empire.^[42] The Han dynasty relied heavily on trade with the Nanyue who produced unique items such as: bronze and pottery incense burners, ivory, and rhinoceros horns. The Han dynasty took advantage of the Yue people’s goods and used them in their maritime trade network that extended from Lingnan through Yunnan to Burma and India.^[43]

During the first century of Chinese rule, Vietnam was governed leniently and indirectly with no immediate change in indigenous policies. Initially, indigenous Lac Viet people were governed at the local level but with indigenous Vietnamese local officials being replaced with newly settled Han Chinese officials.^[44] Han imperial bureaucrats generally pursued a policy of peaceful relations with the indigenous population, focusing their administrative roles in the prefectural headquarters and garrisons, and maintaining secure river routes for trade.^[45] By the first century CE, however, the Han dynasty intensified its efforts to assimilate its new territories by raising taxes and instituting marriage and land inheritance reforms aimed at turning Vietnam into a patriarchal society more amenable to political authority.^[46] The native Luo chief paid heavy tributes and imperial taxes to the Han mandarins to maintain the local administration and the military.^[44] The Chinese vigorously tried to assimilate the Vietnamese either through forced signification or through brute Chinese political domination.^[41] The Han dynasty sought to assimilate the Vietnamese as the Chinese wanted to maintain a unified cohesive empire through a "civilizing mission" as the Chinese regarded the Vietnamese as uncultured and backward barbarians with the Chinese regarding their "Celestial Empire" as the supreme centre of the universe.^[40] Under Chinese rule, Han dynasty officials imposed Chinese culture, including Taoism and Confucianism, its imperial examination system, and mandarin bureaucracy.^[47]

Though the Vietnamese incorporated advanced and technical elements they thought would be beneficial to themselves, the general unwillingness to be dominated by outsiders, the desire to maintain political autonomy and the drive to regain Vietnamese independence signified Vietnamese resistance and hostility to Chinese aggression, political domination and imperialism on Vietnamese society.^[48] Han Chinese bureaucrats sought to impose Chinese high culture onto the indigenous Vietnamese including bureaucratic Legalist techniques and Confucian ethics, education, art, literature, and language.^[49] The conquered and subjugated Vietnamese had to adopt the Chinese writing system, Confucianism, and veneration of the Chinese emperor to the detriment of their native spoken language, culture, ethnicity, and national identity.^[41]

The First Era of Northern Domination refers to the period of Vietnamese history during which present-day northern Vietnam was under the rule of the Han dynasty and the Xin dynasty. It is considered the first of four periods of Chinese rule over Vietnam, the first three of which were almost continuous and referred to as Bắc thuộc ("Northern Domination").